Set a default 'new conversation' type

When clicking create new conversation, it is defaulting to ‘chat’ - we never start new outbound chat, only email. 

This means that for every new email we want to send out of Intercom, we must manually change chat to email. It’s only a small thing, but adding up 100’s of email per week…

Seems reasonable to allow workspaces to select a default new conversation type, I hope.